1. Technical Field
The present invention relates to an ink set and a recording method using the ink set.
2. Related Art
As ink sets for ink jet recording, three color ink sets which are provided with yellow (Y), magenta (M), and cyan (C) inks, or four color ink sets to which black (K) ink is further added have been provided. In addition, for the purpose of obtaining a favorable black and white monochrome image or gray scale, or in order to respond to a demand for higher quality in achromatic color portions (black, gray, and white portions) of a color image, an ink set which includes two types or three or more types of black inks with different carbon black concentrations may be used.
When carrying out recording using an ink set which includes a plurality of types of black inks with different carbon black concentrations, the color reproducibility of the darkest gradation region or the gradation of gray is improved. On the other hand, in a bright gradation region, that is, in a region where recording is carried out using an ink with a lower carbon black concentration, since a lot of ink is used in order to adjust the ink generation amount, not only is the graininess poor, but also a phenomenon which is called “bronzing” is generated in which colors appear to change by reflecting as rainbow colors depending on the viewing angle or the light source environment. When bronzing is generated, the surface of the recorded matter is seen with a different tone from a state of normal diffusion and reflection and appears to have a metallic luster. For this reason, in recorded matter where bronzing is generated, the tone may change and appear unnatural depending on the relative positional relationship with the viewer. Thus, bronzing is not a preferable phenomenon and is desirably removed.
Therefore, using an ink set which uses a plurality of black ink compositions where the content of carbon black is adjusted, there have been attempts to improve the graininess of a bright gradation region and to remove bronzing (for example, refer to JP-A-2010-132909).
However, even using the technique described above, the improvement of the graininess and the removal of the bronzing are not sufficient.